Typically a stringed instrument, such as a guitar, comprises of a series of strings that are strung under tension over a fret board being supported by a nut and saddles of the bridge. The bridge and saddle not only support the strings, but are also important in assuring proper intonation of the guitar strings. The effective string length must be closely controlled in order that the instrument will have the correct octave adjustment. Proper intonation is achieved by fixing the distance of the string from the nut to the bridge. When string distance is accurately fixed can the guitar produce its optimum sound. Adjustable bridges are available for increasing or decreasing the distance from the nut to the bridge allowing the intonation of individual strings to be adjusted. Adjustable bridges may also be used to adjust the height of the strings above the fretboard.
One example of an adjustable bridge is disclosed in U.S. Pat. No. 2,972,923 which discloses a “floating” bridge for use with a vibrato which allows the strings to move during vibrato use. To accomplish this coordinated movement the bridge pivots or rocks on a pair of mounting posts, the diameter of which are smaller than the thimbles into which they were inserted. By coordinating the movement of the strings and the vibrato, the floating bridge reduces the amount of friction imposed by the saddle on the strings when the vibrato is used. Each string is support by a threaded barrel. The intonation of each individual string is adjusted by moving the threaded barrel fore or aft by turning a screw associated with the barrel. In this manner the length of each string is adjusted individually be turning a screw and moving the associated barrel. The height of each string is also adjusted individually by turning a pair of height adjustment screws associated with each barrel.
Use of prior art adjustable bridges with certain guitar styles, particularly those equipped with vibratos, results in adequate string tension being applied to each of the individual barrels of the bridge. The lack of tension may result in strings being displaced from their associated barrel during playing. The lack of tension may also cause one or both barrel height adjustment screws to loosen during playing. The loosening of the height adjustment screws may cause unwanted string vibration and decreased sound quality.
The need to adjust the length and height of each string individually by adjusting either one or two screws associated with each barrel also makes proper intonation adjustment difficult and time consuming. Further, the position and arrangement of barrel length adjustment screws in prior art bridges relative to the strings made them difficult to access and often resulted in unwanted contact between the strings and the screw during playing.
Accordingly, what is needed is an adjustable bridge that improves the amount of tension applied by the strings to the saddle elements, thereby preventing the strings from becoming displaced during playing, reducing unwanted string vibration and improving sound quality. What is also need is an adjustable bridge that is easily and quickly adjusted and minimizes or eliminates contact between the strings and the adjustment means.